Anti seize on coupler set screws?

[skunther]

In the process of replacing my PSS bellows, I had to replace the coupler set screws as they got mangled in the removal (they were quite seized) - they did finally come out, but are no longer usable, so I got some used replacement set screws (they are exceptionally hard to find in Bellingham WA for some reason). I am wondering if I should use antiseize on them or loctite instead. I will install seizing wire, but don’t want to have issues with removal next time. I also don’t want them coming loose during operation.

Also, the coupler mounting bolts (to the transmission mounting plate) were not very tight when I removed them. I could rotate each bolt/nylock by hand. Does anyone know how much the 4 mounting bolts should be torqued? Also, how much the coupler set screws should be torqued?

Much thanks.

 

[dlochner]

The coupler set screws should be as tight as you can get them and then wired into place so the screw can't back off. The flange to transmission mounting bolts should be as tight as you can get them.

Prior to remounting the coupling, clean all the rust and corrosion off of it. Then once mounted and everything is secured spray the coupling with an anti-corrosion spray like the CRC Anticorossion spray.

For more info see this article:

https://stevedmarineconsulting.com/wp-content/uploads/2019/06/ShaftCouplings179FINAL-PBB.pdf

 

[skunther]

Thank you.
No mention of antiseize or loctite… best to skip using either of them?

 

[dlochner]

Thank you.
No mention of antiseize or loctite… best to skip using either of them?

No antiseize, that is essentially a lubricant which makes it easier for the bolt to come loose. Lactate won't work on the nyloc nuts because it won't stick to the nylon.

 

[skunther]

I meant loctite on the coupler set screws.

 

[dlochner]

I meant loctite on the coupler set screws.

I don't think it will hurt, use the nonpermanent type. Sooner or later that coupling is coming off again.

 

[JamesG161]

PYI Inc. | PSS Maintenance Kits
Kits for PSS seal.

Use @dlochner Red Lithium Grease on the other stuff for anti-seize.

Jim...

 

[Ralph Johnstone]

About the only thing that's going to keep that area in reasonable shape is continued maintenance and a protective coat such as Fluid Film or an easily removed anti corrosion spray. I like FF because it's like penetrating oil when applied and then dries to a greasy, gummy mess. Watch out for the gland slinging water over the couplings.

I would deep six the nylocks on the four bolts and instead go with lock washer and straight nuts. The manual specs the torque at "good and f***ing tight" The factory bolts are grade 8 so lean into them. Use new fasteners if the old one are rusty but GRADE 8 or whatever is close. I wouldn't bother with Loctite but do keep an eye on them from year to year. Make the two hub nuts good and tight and wire them to eliminate the chance of that first CCW movement. Think about it before you wire them.

 

[rgranger]

Lactate won't work on the nyloc nuts because it won't stick to the nylon.

Thats what she said....

Auto-correct... can be your worst enama

 

[Ralph Johnstone]

OMG. I would think your worst enema would be confusing "equate" with "Loctite".

​

 

[Tally Ho]

In the process of replacing my PSS bellows, I had to replace the coupler set screws as they got mangled in the removal (they were quite seized) - they did finally come out, but are no longer usable, so I got some used replacement set screws (they are exceptionally hard to find in Bellingham WA for some reason). I am wondering if I should use antiseize on them or loctite instead. I will install seizing wire, but don’t want to have issues with removal next time. I also don’t want them coming loose during operation.

Also, the coupler mounting bolts (to the transmission mounting plate) were not very tight when I removed them. I could rotate each bolt/nylock by hand. Does anyone know how much the 4 mounting bolts should be torqued? Also, how much the coupler set screws should be torqued?

Much thanks.

I believe that the set screws on the PSS collar are 1-time use…

Not intended to be reused.

Greg

 

[TimFromLI]

I serviced mine last year, I used permatex anti seize on both the coupler set screws and the coupler to shaft. I am having second thoughts about whether I should have put it on the shaft. The seizing wire should keep the screws in place. I had a hard time finding new set screws- I finally found them on ebay. My old ones were probably ok but I wanted new. And as Greg said, always use new set screws on the pss collar.

 

[dlochner]

I am having second thoughts about whether I should have put it on the shaft.

Get a split coupling and coat it with an anti-corrosion spray.

When trying to keep the shaft attached to the transmission, friction is your friend.

 

[skunther]

Get a split coupling and coat it with an anti-corrosion spray.

When trying to keep the shaft attached to the transmission, friction is your friend.

Interesting - any thoughts on the pros and cons of a split coupler? It seems to introduce the potential for more play in the coupler on the shaft as there are more moving parts. Would require specific torques and loctite on the securing bolts too?

 

[Ralph Johnstone]

It seems to introduce the potential for more play in the coupler on the shaft as there are more moving parts.

It seems to be the way to go if you've got deep pockets, and in particular, if you've got a mechanical seal rather than a stuffing box. Me, I can't afford to travel in those circles.

Would require specific torques and loctite on the securing bolts too?

Don't have one but I can imagine the instructions would require exactly that. @Tally Ho , can you comment on your split coupling ?

 

[dlochner]

Interesting - any thoughts on the pros and cons of a split coupler? It seems to introduce the potential for more play in the coupler on the shaft as there are more moving parts. Would require specific torques and loctite on the securing bolts too?

The big pro is ease of installation and removal. Because it is easy to remove and install there is less opportunity for damage to the transmission, shaft, and coupling. When installing the coupling is snug getting the nuts as tight as you can with a ⅜" ratchet is enough although there is probably some engineering document with a specific amount, however there were no instructions about torque.

The key and key way prevent slipping.

 

[Tally Ho]

It seems to be the way to go if you've got deep pockets, and in particular, if you've got a mechanical seal rather than a stuffing box. Me, I can't afford to travel in those circles.

Don't have one but I can imagine the instructions would require exactly that. @Tally Ho , can you comment on your split coupling ?

I don’t have a split coupling. When replaced my shaft, I didn’t think about using a split coupling. But I should have.

A year or 2 after I replaced the shaft, I decided to upgrade to a Volvo dripless shaft seal. But of course, this meant removing the coupling. Mine was still new enough that it wasn’t too hard to get off, but I think a split coupling would make that easier. And eventually, I will need to replace the Volvo shaft seal…and by then my coupling look as bad as the one I replaced when I replaced the shaft…and that one took 2 days to press off :-(

I have coated mine with lanocote to try and keep it from rusting.

Greg

 

[jssailem]

I used a split coupling to replace the 35 year old coupling removed. Cost for the split coupling was not much. about 18% of the new shaft and machining for the shaft to fit & face
Price varies based on shaft size and length...

From Fisheries Specifications:
All things being equal, split couplings are easier to install and remove than solid couplings.
• Order a "No Bore" coupling for machining a custom shaft size
• "No Bore" split couplings come with a 3/4" to 1-1/4" pilot bore
• codes for transmission types permit matching to your transmission bolt pattern: A=Allison, B/W=Borg Warner, C=Capitol, H=Hurth, N=Newage, P=Paragon, TD=Twin Disc, VP=Volvo Penta, Y=Yanmar, ZF=ZF


There appears to be a corrosion reduction coating on the coupling. With the association of saltwater I expect surface corrosion will occur. I will try to minimize this so that the coupler can be reused in the future, but it is likely that the coupler will need to be refaced so I see it as being able to save the shaft and the coupling becomes a consumable.

I did not have a specific torque value. The coupler was a press fit. There is a bronze key used to match the couple to the shaft. I used lock washers and tightened the bolts as much as possible.

 

[skunther]

… it is likely that the coupler will need to be refaced so I see it as being able to save the shaft and the coupling becomes a consumable.

Can you clarify what you mean by this? Why would it need refacing, and how does it save the shaft?

I have a 1” shaft with a Yanmar transmission. Couldn’t I put a 1” split coupler with Yanmar bolt pattern on without any further modifications?

 

[jssailem]

Sure.
My old coupler was rusted onto the shaft. After inspection of the stuffing box the shaft was damaged and needed to be replaced. I cut the old shaft.
A new coupler gets milled to fit the shaft. The face that gets milled at 90 degrees to the shaft and milled smooth to face the transmission.
If you can remove an old coupler undamaged you’ll want to assure you can fit it back on the shaft and that the face will be 90 degrees to the shaft. If not the alignment of the shaft might be a problem. Just like your disk break’s rotor. They surface the parts for a perfect fit. If there is not enough material to surface you need to replace, or try to reassemble and then attempt to realign.